1. Field of the Invention
The present invention relates to a keyboard apparatus having hammer bodies each configured to impart inertia to a key depressing motion.
2. Description of Related Art
There has been conventionally known a keyboard apparatus having hammer bodies each corresponding to a hammer of an acoustic pianos, for the purpose of imparting inertia to a key depressing motion. Further, there has been known an acoustic piano designed to cause a feeling which approximates to a click feeling generated when a jack escapes in a key depression stroke.
In an apparatus disclosed in the following Patent Literature 1, for instance, a recess or a protrusion for giving the click feeling is provided below a lower surface of a key, and a sliding protrusion or recess is provided on a hammer body so as to correspond to the click-feeling giving recess or protrusion provided on the key. In the key depression stroke, the recess and the protrusion come into sliding contact with each other, thereby generating the click feeling.
In an acoustic piano, a key is depressed in various manners. Where the key is depressed slowly (i.e., in the case of weak key depression), the key and the hammer are held in abutting contact with each other throughout the key depression stroke. Where the key is depressed strongly or quickly beyond a certain level (i.e., in the case of strong key depression), the key is separated from the hammer in the middle of the key depression stroke and the hammer may freely pivot. Accordingly, the jack escape feeling is generated in the weak key depression, but is not generated in the strong key depression.    Patent Literature 1: JP-A-4-166994